CREATE TRIGGER VIEW_LINKS_AI0 FOR VIEW_LINKS
INACTIVE AFTER INSERT POSITION  0 
as
DECLARE VARIABLE A INTEGER;
begin
  execute procedure getcaninsert(new. "father" ,new. "children" )
    returning_values :A;
  if (A= 1 ) then
    begin
      insert into  "Links" ( "father" , "children" ) values (new. "father" ,new. "children" );
    end
end

CREATE TRIGGER  "Links_AI0"  FOR  "Links" 
ACTIVE AFTER INSERT POSITION  0 
as
DECLARE VARIABLE A INTEGER;
begin
  execute procedure getcaninsert(new. "father" ,new. "children" )
    returning_values :A;
  if (A= 0 ) then
    EXCEPTION MY_EXCEPTION;
  when exception MY_EXCEPTION do A= 0 ;
end